asked on 3/25/2004

qow 21 : Fading/Blending effects of Pictures

hi experts,

i will restart again qow (question of the week)
(thanks robert_marquardt for remembering :-))

each week i will introduce a new simple? question.

now qow 21

against the rules of the previous qows
all expert are allowed to solving this question.

the rule are:
- you must post your source here in this question.
- each different solution gets the points provided with this question
(means one expert can get multiple points, if the solutions are different)
- bonus (only for one solution), if a solution is special simple or clever,
or provides mutliple effects, this solution gets double-double-points (4x)

well the question is:

How to make fading/blending effects with two pictures?

Scenario Description:
i have two pictures, and want to see one after one with a nice noticeable,
fading/blending effect on my form.

for fast Validations, if you can, additional to the source-posting here,
send me your compiled project to
kretzschmar@experts-exchange.com

each different solution may get 125 pts (a-graded).

this question will be closed after 7 days.

have fun and let see

meikl ;-)

Delphi

Last Comment

kretzschmar

4/20/2004

ASKER CERTIFIED SOLUTION

Jacco

3/25/2004

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Jacco

3/26/2004

Here is a blend for use with the framework.

Regards Jacco

PS: There is a small bug in the framework:
...
if not Fade then
begin
img.Invalidate; <<<< need to be inserted to show the last step to user
...

function TfrmFade.Blend: Boolean;
type
TRGBQuadArray = array[0..0] of TRGBQuad;
PRGBQuadArray = ^TRGBQuadArray;
var
i, s, d: PRGBQuadArray;
liX, liY, liSteps: Integer;
begin
liSteps := 500 div Speed;
for liY := 0 to imgHeight-1 do
begin
i := img.Picture.Bitmap.ScanLine[liY];
s := src.Picture.Bitmap.ScanLine[liY];
d := dst.Picture.Bitmap.ScanLine[liY];
for liX := 0 to imgWidth-1 do
begin
i[liX].rgbRed := EnsureRange(Round(s[liX].rgbRed + (d[liX].rgbRed - s[liX].rgbRed ) * (Step / liSteps)), 0, 255);
i[liX].rgbGreen := EnsureRange(Round(s[liX].rgbGreen + (d[liX].rgbGreen - s[liX].rgbGreen) * (Step / liSteps)), 0, 255);
i[liX].rgbBlue := EnsureRange(Round(s[liX].rgbBlue + (d[liX].rgbBlue - s[liX].rgbBlue ) * (Step / liSteps)), 0, 255);
end;
end;
Inc(Step);
Result := not (Step = liSteps + 1);
end;

kretzschmar

3/26/2004

ASKER

thanks jacco,

i will validate your solutions later,
but a preview over your source looks good

meikl ;-)

Member_2_248744

4/1/2004

I thought there would be more entries for this. . . . you still looking for some blenders?

kretzschmar

4/1/2004

ASKER

well,
i expected also more participants :-(

>you still looking for some blenders?
yes, but selfmade

this question will be closed in about 10 hours.

meikl ;-)

SOLUTION

Member_2_248744

4/1/2004

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kretzschmar

4/5/2004

ASKER

sorry,
got no time for evaluation yet,
i will keep it open until next weekend.

be patient

meikl ;-)

kretzschmar

4/19/2004

ASKER

if you both agree,
i would spent 250 pts each.

meikl ;-)

Member_2_248744

4/19/2004

It seems you are a busy person :-)
Thank you meikl, for the time and effort you have put here at EE ! !

you can do whatever seems best to you, I do not really need the points. . . . I put this fade thing here so it might help somebody. . .

I was really hoping for some more partisipation, entries, for this qow
but EE seems so different now to me? ?

Jacco

4/19/2004

I agree with Slick812.

I had hoped for some more response too. Maybe the stakes aren't high enough?

It might work with 1 high price and low frequency maybe monthly.

Regards Jacco

kretzschmar

4/20/2004

ASKER

well, thanks both :-))

>It might work with 1 high price and low frequency maybe monthly.
usually i have not the time to do it weekly, so i will take this suggestion

>I was really hoping for some more partisipation, entries
i hoped this too, well maybe nexttime i will reask this q again

meikl ;-)